/* *  ebt_log * *	Authors: *	Bart De Schuymer <bdschuym@pandora.be> * *  April, 2002 * */#include <linux/netfilter_bridge/ebtables.h>#include <linux/netfilter_bridge/ebt_log.h>#include <linux/module.h>#include <linux/ip.h>#include <linux/if_arp.h>#include <linux/spinlock.h>static spinlock_t ebt_log_lock = SPIN_LOCK_UNLOCKED;static int ebt_log_check(const char *tablename, unsigned int hookmask,   const struct ebt_entry *e, void *data, unsigned int datalen){	struct ebt_log_info *info = (struct ebt_log_info *)data;	if (datalen != EBT_ALIGN(sizeof(struct ebt_log_info)))		return -EINVAL;	if (info->bitmask & ~EBT_LOG_MASK)		return -EINVAL;	if (info->loglevel >= 8)		return -EINVAL;	info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0';	return 0;}struct tcpudphdr{	uint16_t src;	uint16_t dst;};struct arppayload{	unsigned char mac_src[ETH_ALEN];	unsigned char ip_src[4];	unsigned char mac_dst[ETH_ALEN];	unsigned char ip_dst[4];};static void print_MAC(unsigned char *p){	int i;	for (i = 0; i < ETH_ALEN; i++, p++)		printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':');}#define myNIPQUAD(a) a[0], a[1], a[2], a[3]static void ebt_log(const struct sk_buff *skb, const struct net_device *in,   const struct net_device *out, const void *data, unsigned int datalen){	struct ebt_log_info *info = (struct ebt_log_info *)data;	char level_string[4] = "< >";	union {struct iphdr iph; struct tcpudphdr ports;	       struct arphdr arph; struct arppayload arpp;} u;	level_string[1] = '0' + info->loglevel;	spin_lock_bh(&ebt_log_lock);	printk(level_string);	printk("%s IN=%s OUT=%s ", info->prefix, in ? in->name : "",	   out ? out->name : "");	printk("MAC source = ");	print_MAC((skb->mac.ethernet)->h_source);	printk("MAC dest = ");	print_MAC((skb->mac.ethernet)->h_dest);	printk("proto = 0x%04x", ntohs(((*skb).mac.ethernet)->h_proto));	if ((info->bitmask & EBT_LOG_IP) && skb->mac.ethernet->h_proto ==	   htons(ETH_P_IP)){		if (skb_copy_bits(skb, 0, &u.iph, sizeof(u.iph))) {			printk(" INCOMPLETE IP header");			goto out;		}		printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u,",		   NIPQUAD(u.iph.saddr), NIPQUAD(u.iph.daddr));		printk(" IP tos=0x%02X, IP proto=%d", u.iph.tos,		       u.iph.protocol);		if (u.iph.protocol == IPPROTO_TCP ||		    u.iph.protocol == IPPROTO_UDP) {			if (skb_copy_bits(skb, u.iph.ihl*4, &u.ports,			    sizeof(u.ports))) {				printk(" INCOMPLETE TCP/UDP header");				goto out;			}			printk(" SPT=%u DPT=%u", ntohs(u.ports.src),			   ntohs(u.ports.dst));		}		goto out;	}	if ((info->bitmask & EBT_LOG_ARP) &&	    ((skb->mac.ethernet->h_proto == __constant_htons(ETH_P_ARP)) ||	    (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_RARP)))) {		if (skb_copy_bits(skb, 0, &u.arph, sizeof(u.arph))) {			printk(" INCOMPLETE ARP header");			goto out;		}		printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d",		       ntohs(u.arph.ar_hrd), ntohs(u.arph.ar_pro),		       ntohs(u.arph.ar_op));		/* If it's for Ethernet and the lengths are OK,		 * then log the ARP payload */		if (u.arph.ar_hrd == __constant_htons(1) &&		    u.arph.ar_hln == ETH_ALEN &&		    u.arph.ar_pln == sizeof(uint32_t)) {			if (skb_copy_bits(skb, sizeof(u.arph), &u.arpp,			    sizeof(u.arpp))) {				printk(" INCOMPLETE ARP payload");				goto out;			}			printk(" ARP MAC SRC=");			print_MAC(u.arpp.mac_src);			printk(" ARP IP SRC=%u.%u.%u.%u",			       myNIPQUAD(u.arpp.ip_src));			printk(" ARP MAC DST=");			print_MAC(u.arpp.mac_dst);			printk(" ARP IP DST=%u.%u.%u.%u",			       myNIPQUAD(u.arpp.ip_dst));		}	}out:	printk("\n");	spin_unlock_bh(&ebt_log_lock);}static struct ebt_watcher log ={	.name		= EBT_LOG_WATCHER,	.watcher	= ebt_log,	.check		= ebt_log_check,	.me		= THIS_MODULE,};static int __init init(void){	return ebt_register_watcher(&log);}static void __exit fini(void){	ebt_unregister_watcher(&log);}module_init(init);module_exit(fini);MODULE_LICENSE("GPL");